Process of drying filaments



VNov. 25, 194i. A. o. HURxTHA-L ET 11u. 2,264,207

PROCESS OFDRYING' FILAMENTS Filed Marchi, 1940 4 Sheets-Shea?l l if@ P' 5.5"/

Nov. 25, 1941.

A. O. HURXTHAL ET AL PROCESS OF DRYING FILAMENTS Filed March 2, 1940 4 Sheets-Sheet 2 Nv. 25, 1941. AQo. HURXTHAL E T AL., '2,264,207

PROCESS 0F DRYING FILAMENTS Filed March 2, 1'940 4 sheets-sheet 5 Nov. 25, 1941 A. O. HURXTHAL ET AL PROCESS OF DRYING FILAMENTS -Filed March 2, i940 4 Sheets-SheeI 4 Patented Nov. 25, 1941 UNITED STATES PATENT OFFICE raocEss or name. maMEN'rs of Pennsylvania Application March 2, 1940, Serial No. 322,022

Claims.

This invention relates to the drying of textile strands composed of single threads or filaments of natural or synthetic substance, or of two or more combined laments or threads etc. of one or the other or both substances. y

The present invention is directed to the processing of a textile strand while undergoing one stage of manufacture or processing, wherein the strand is in a wet or damp condition and is wound in a closely compacted package composed of successive convolutions or turns arranged in superposed layers; and wherein the strand is withdrawn from 'said turns, convolutions and layers progressively and rewound in another package either of the same kindand shape as the primary package or of a diiferent kind or shape. The present invention contemplates drying the strand While undergoing transformation from one to another package regardless of the type or shape of either.

The present. invention more particularly relates to the drying of synthetic filaments known as artificial silk, rayon etc. which, when initially formed into a continuous strand is in a Wet condition and requires drying.

According to one prior art process, the synthetic filaments are dried immediately after formation and processing, or as each single lament emerges from a washing liquid through which it is passed after the lament has attained its solidified form. The dried strands, under this particular process, are each wound directly and immediately into a conical or cylindrically shaped package, or on a Y spool or other core element for future use or advantage, i. e. no strand, after drying, is of uniform quality throughout its length, as a result of uneven shrinkage occurring between those portions constituting the inner, outer, and inter- 10 mediate layers respectively of the package.

In order to reduce the drying time, other prior art processes contemplate the rewinding of each wet strand from the primary package into an intermediate package of the skein type. These l5 skeins are then hung on poles and passed through package drying method it is still subject to the disadvantage of non-uniform quality throughout the length of the strand, because of the relatively small percentage of the length of the strand which lies on the outside of the mass forming the skein and therefore exposed to the drying medium; and as a result of Amoisture running into the lower parts of the skeins, which causes the upper parts of the skeins to dry quicker than the lower parts thereof and results in the different portions of the different turns or convolutions oi' which a skein is composed shrinking unevenly.

The dried laments are subsequently withdrawn from the intermediate skein packages and each wound into a cylindrically or conical shaped further processing. This method of drying is ultimate package which may take the form of a subject to severe mechanical problems and regulations which are extremely diiiieult to control,

thus this particular process is not extensively utilized.

spool or bobbin, for future use or further processing, as noted above.

The objects of the present invention are to reduce the drying time of the primary package and However, in most processes of the prior art 40 skein drying PIOCESSGS; t0 eliminate the l10n-unithe single filaments, after initial formation and washing, are wound into cakes, within hollow containers, or the filament is wound on the outside Vof a core cylinder, in each instance in the form of superposed layers of successive convolutions.

In some instances, the single filaments are dried while still in the primary packages, by loadtormity of quality to which the primary package and skein package drying processes are subject; to eliminate the rewinding step of the skein drying process; and to overcome the disadvantages of the direct drying processes. To this end the present invention contemplates the transformation of the Aindividual strands from onev or the other types of primaary package directly into one ing the cakes (removed from the containers), or or the other types of ultimate package, and the the wrapped cylinders, on racks or trucks and subsequently passing the loaded supports through long drying tunnels in which air is maintained in circulation and wherein the temperature and hudryingofthestrand: I

(a) v As it is beingvwithdrawn from'ithe primary Package;

(b) As it is being rewound on th`e ultimate midity is necessarily controlled very accurately. 66 package; or

(c) In transit between the two packages in addition to (a) or (b) or (a) and (b).

In carrying out the preferred embodiment of the process of the present invention, exposed turns of the strand on one surface of the primary package are initially exposed to a drying medium as the strand is withdrawn from said turns progressively and successively, to effect drying of the strand.

In another embodiment of the invention the above noted exposure of the surface of the primary package to the drying medium may be \em ployed to start the drying and may be said to effect a rst stage drying of the strand. en, as the strand passes from the primary package to the ultimate package, i. e. to the cone, cylinder, spool, bobbin, etc. on or into which the strand is being rewound, the naked strand may be directly exposed to the drying medium to receive a second or final stage of drying.

In other instances the wet strand may be withdrawn from the primary package and initially dried in transit to the second package, to receive its nal drying as it is being rewound in the second package, by exposing the surface of the second package to the drying medium as the strand is wound thereon.

In other instances the drying of the strand may take place solely as it is being wound in the convolutions of which the ultimate package is formed, with the exposed layers coming under the influence of the drying medium to receive final drying.

In other instances, the drying may be inaugurated as the strand is unwound from the primary package, continued while the strand is in transit between the primary and ultimate packages', and finished as the strand is rewound in the ultimate package.

Uniformity of quality throughout the length of each strand is assured under the process of the present invention as outlined above, by reason of the control afforded by the uniform saturation of the Wet bulk of the primary package from which the strand is being withdrawn causing the strand to be in a uniformly moistened condition when it -rst makes contact with the drying medium, and uniformity of the drying medium to which the strand is exposed, causing the strand to be uniformly dried as it is Wound into the ultimate package; and by reason of the shrinkage attending drying progressing uniformly along the length of the strand as it drys during and between its withdrawal from the wet package and its rewinding on the dry package.

By the drying method of the present invention the drying time is reduced well below that of either the primary package or skein package drying methods, to a point closely approaching that of the direct method; the one step of handling required to rewind the strand from the dry -skein to the ultimate cone etc. is eliminated; and the process does not require the use of extremely high temperatures necessary for effecting drying under the direct method which is frequently injurious to the duality` f the PrOduCt, thus assuring a uniform product.

Any suitable apparatus may be used to effect the drying of the strand according to the present invention, as will be obvious from the following disclosure relating to two simple forms of mechanism which can be used in carrying 0ut the process.

. In the accompanying dlaWmgS Fgg, 1 diagrammatically illustrates an apparectly in conjunction with a conventional winding machine for rewinding the strand into the second package, with a running-loop strand accumulator between the two packages;

Fig. 5 is a section taken on the line 5-5, Fig. 4;

Fig. 6 shows direct winding from the primary package to the package being wound on the conventional Winder.

In Figs. 1, 2 and 3 of the drawings, the wet primary package, in this instance having the form of a cake, is illustrated at A. The ultimate package is illustrated at B, and the single strand in transit between the primary and ultimate packages is illustrated at C. The process is confined to and carried on within a suitable enclosure or chamber I, the bottom of which is open and connected to the outlet side 2 of a centrifugal blower casing 3. In the casing 3 is mounted the rotary impeller 4 of the blower, said rotor being secured to a shaft 5 of a driving motor 8.

Projecting into the chamber I from the rear wall 1 thereof, is a hollow suction box structure 8 which communicates with an air return conduit 9 of the blower 3, said conduit being connected to the intake side I0 of said blower.

The upper wall II of the suction box 8 is provided with an opening I2, at spaced intervals around the periphery of which are vertical posts I3. The posts I3 are connected at their upper ends by cross bars I4 and form a centralizing support for the wet primary package A.

Concentric with the opening I2 and package A is a cage I5 which encloses the package A and is provided with vertical slots I6, in the present instance, through which air, driven upwardly into the chamber I by the blower 3, passes under high velocity and impinges against the outer surface of the package A, causing complete or partial drying of the outer turns or convolutions of the strand C of which the package A is composed. y

Directly above the cage I5 is a lower wall I1 l of a secondary chamber I8, through which the strand C passes in transit from the primary wet package A to the second or ultimate package B. The chamber I8, in addition to the bottom I1 thereof, is provided with side walls I9, I9 and a top wall 20 each of which extends from the rear wall 1 of the chagnber I to the front wall 2I thereof, thus providing air channels 22, 22 between the side walls I9, I8, of the chamber I8 and the side walls 23, 23 of the enclosure I.

.Air driven upwardly through the enclosure I,v

after passing around the outside of the suction box 8, moves upwardly through the passages 22 into an upper chamber 24, formed between the top Wall 28 of the chamber I8 and the top wall 25 of the enclosure I.

'I'he top wall 20 of the chamber I8 is provided with an opening 26 in which the package B is rotatably mounted for winding the strand C thereon. Extending around the top of the package B, and bridging the opening 26, is a cage 21 which is provided with longitudinal slots 28 through which the air driven upwardly into the strand C in transit to effect drying of the strand, l

said air being evacuated from the chamber I8 through a port 29, at the lower end of the chamber I8, which communicates with the return duct 9 of the blower 3.

Mounted within the return duct 9, in the present instance, is a series of heating units 30, around which the air returning to the blower 3 through the duct 9 must pass, and by which said air in circulation is heated to the desired temperature.

I'he strand C is drawn from the package A through a guide eye 3l and passes to and through a second eye 32, which is carried by a longitudinally reciprocable traverse bar 33, and from which the strand passes to the ultimate dry package B.

The package B is rotated by a shaft 34 which, in the present instance, is operatively connected to a motor or other source of power 35, through pulleys 36 and 31 and a drive belt 38, the pulleys 3B and 31 being of the step or cone type by which various speeds may be given to the winding shaft 34.

The traverse bar 33 is provided with a cam follower 39, which is maintained against the periphery of a heart-shaped traverse cam 48 by a spring 4I, the cam 40 being secured to a shaft 42 on which is provided a pulley 43. The pulley 43 is connected by a belt 44 to a pulley 45 mounted on the shaft 34 and by which longitudinal reciprocation of the guide eye 32, relative to the length of the package B, is accomplished to lay the strand C in successive convolutions and superposed layers on the core 46 upon which the ultimate package B is formed.

In the present instance, the package B is illustrated as having the form of a cylinder but which may take the form of a cone, etc. Any suitable means may be provided for detachably connecting the core member of the package B to the driving shaft 34, by which the core member would be rotated to wind the strand C thereon and cause said strand to be drawn from the convolutions in the primary wet package A.

In the present instance, a door 50 is provided in the front wall 2I of the chamber or enclosure I, by which access may be had to the interior of the enclosure for removal and replacement of the packages A and B, and for threading the strand C from the one to the other. In the present instance, access to the interior of the cage I5, in which the primary package A is mounted, may be had through a hinged section 5I of the bottom wall I1 of the compartment I8.

In .the present instance, the ultimate package B is shown as being held between a pair of frustoconical centering and driving members 52 and 53, the member 52 being rigidly secured to the inner end of the drive shaft 34, while the member 53 evacuated from the duct 9 and to be driven upwardly into the enclosure I, wherein a suitable pressure is built up. 'I'his air under pressure passes through the slots I6 of the cage I5 and through the slots 28 in the cage 21, by which the velocity of the air is materially increased. This air under high velocity impinges against the packages A and B, causing a drying action to take place in the outer convolutions of the strand C in each of said packages.

The impinging air then passes downwardly through the center of the package A and through the opening I2 of the upper wall I I of the suction box 8 to the return duct 9.

'I'he air impinging upon the package B passes downwardly through the compartment I8, under high velocity, and is evacuated through the opening 29 into the duct 9.

The duct 9, being connected to the intake of the blower 3, is continually under a pressure considerably lower than that built up in the casing or enclosure I, by which high velocity of the air past the strand C in both packages, and in transit therebetween, is maintained.v

While the apparatus shown in the drawings illustrates but one strand undergoing drying, it will be understood that the apparatus may be made in such proportions as to accommodate any desired number of wet and dry packages simultaneously with a strand passing from each of the wet packages to a corresponding dry package, without departing from the spirit of the invention; and any suitable means may be provided for circulating, heating, and/or humidifying the air in circulation.

In that form of the invention shown in Figs. 4 and 5, the primary packages A are located n slotted velocity increasing cages I5a within an air chamber or conduit Ia. connected to the discharge side of a blower casing 3a and the strand CI is led from the outside surface of the package AI through an opening 3Ia in the apex of a hollow cone I'Ia to a suitable4 accumulator Ill.4

The strand CI is formed into running loops 6I within the accumulator 60 around freely rotating rollers 62, 63 disposed at the opposite ends respectively of a central partition 64 in the accumulator and which divides the same into compartments 60a and 60h.

The rollers 62 and 63 may be mounted with their respective axes at an angle to each other or the rollers may be tapered, or both, to permit reduction in the loops 6I as a result of shrinkage of the strand as it dries in the accumulator, and to feed the running loops along the rollers from the point 65 wherein the strand CI enters the accumulator to the point 66 where it leaves the accumulator.

From the accumulator the dried strand C passes through the traversing eyes (not shown) to the packages B on the winding spindles of any conventional type of winding machine, for remounted on one end of a retractible shaftv154;A

about which is mounted a spring 55 which bears against a collar 58 secured to the shaft 54 and tends to force the element 53 into contact with one end of the core of the package B.

With the apparatus diagrammatically illustrated in the drawings, rotation imparted to the rotary impellor 4 by the motor 6, causes air to be winding the dried strand CI into the second or ultimate packages BI.

The air after impinging upon the outer surface of the package AI passes through the perforated bottom I'Ia of the cage I5a into the return duct 9a to the intake side of the blower casing 3a.

. If--desired, the upper end of the core opening al of the wet package AI may be closed by a plug 61 and the lower end of said opening caused to register with a pipe 68 connected to a high vacuum pump to cause the air to pass through the package from the outside thereof to the core thereof preparatory to the air entering the cage I5a through the velocity increasing slots thereof impinging upon the outer surface of the package to effect drying of the outer convolutions of the strand CI as it is withdrawn therefrom.

Air is delivered to and removed from the accumulator 60 through conduits 69 and 10 respectively connecting the conduits I a and 9a respectively with the compartments 60a and 60h of the accumulator 60. The partition may be perforated to baffle the air passing from the compartment 60a to compartment 60h or may be removed entirely, if desired. Normally there would 'be sufficient space between the margins of the partition and the rollers and the rollers and the Walls of the accumulator to permit passage of air from one compartment to the other.

With this apparatus, lthe strand CI is dried partly in the convolutions forming the outer surface of the wet package AI and nished in the accumulator 60 before being wound on the second package BI.

With the arrangement shown in Fig. 6 the strand C2 would be dried completely on and as it leaves the outer surface of the wet package, through the cone Ila, before being wound directly on the second package B2, without use of the accumulator 60.

While the foregoing description and the appended claims are directed to and recite a textile strand it will, of course, be understood that the process is equally applicable to the drying of any strand, filament, thread, yarn, string, etc. of a like character and regardless ofthe use to which the strand, etc. may be put ultimately, as it will be obvious thatl the process is equally applicable to drying strands, etc. which may be used for any number of purposes and which may not be aptly termed textiles for example, such as cords laid in automobile tires and which are not interwoven with each other, or wrappings for fishing rods, package bindings, sewing thread, sh line, etc. Therefore, the term ftextile strand as used in the appended claims is to be considered all inclusive and Vnot restricted to any particular kind of strand used for any particular purpose.

We claim:

l. The process which consists in withdrawing a continuous textile strand progressively from one surface of a wet closely compacted package composed of said strand, rewinding said strand into a second package progressively on one surface thereof, and forcibly plowing a drying medium against both of. said surfaces and thereby drying said strand from start to finish in a single passage thereof from the one to the other of said packages.

2. The process which consists in withdrawing a continuous textile strand progressively from one surface of a wet closely compacted package composed of said strand, rewinding said strand into a second package progressively on one surface thereof, and forcibly blowing a drying medium against both of said surfaces and the strand in transit between said packages and thereby drying said strand from sta-rt to finish in a single passage thereof from the one to the other of said packages.

3. The process which consists in withdrawing a continuous textile strand progressively from one surface of a wet vclosely compacted package composed of said strand, rewinding said strand into a second package progressively on one surface thereof, and forcibly blowing a drying medium against said surface of said wet package and thereby drying said strand from start to finish in a single passage thereof from the one to the other of said packages.

4. The process which consists in forcibly blowing a drying medium against one surface of a wet closely compacted package composed of a continuous textile strand and withdrawing said strand progressively from the exposed surface of the package to expose underlying portions of the package successively to said drying medium and thereby drying said strand from start to nish while exposed to the drying medium being blown against the wet package solely.

5. The process which consists in forcibly blowing a drying medium against one surface of a wet closely compacted package composed of a continuous textile strand and withdrawing said strand progressively from the exposed surface of the package in the presence of said drying medium to dry the strand completely in one single exposure to said drying medium as it is withdrawn from the package.

6. The process which consists in withdrawing a continuous textile strand progressively from one surface of a wet closely compacted package composed of said strand, and during said withdrawal impinging a gaseous drying medium at high velocity against that surface of the package from which said strand is being withdrawn thereby drying the strand from start to nish while exposed to the drying medium impinging against the Wet package solely.

7. The process which consists in withdrawing a continuous textile strand progressively from one surface of a wet closely compacted package composed of said strand, rewinding said strand into a second package progressively on one surface thereof, accumulating a predetermined length of said strand in transit from the one to the other of said packages in spaced running loops and exposing one of said package surfaces and said accumulation to a drying medium for drying said strand.

8. The process which consists in withdrawing a continuous textile strand progressively from one surface of a wet closely compacted package composed of said strand, rewinding said strand into a second package progressively on one surface thereof, accumulating a predetermined length of said strand in transit from the one to the other of said packages in spaced running loops and exposing that surface of the first said package from which the strand is being withdrawn and said accumulation loops to a drying medium for drying said strand.

9. The process which consists in withdrawing a continuous textile strand progressively from one surface of wet closely compacted package ccmposed of said strand, impinging a gaseous drying medium against said surface as the strand is withdrawn therefrom, and simultaneously passing said medium through said package from said surface to an opposite surface thereof.

ll0. The process which consists in withdrawing a continuous textile strand progressively from one surface of wet closely compacted package composed of said strand, impinging a gaseous drying medium against said surface as the strand is withdrawn therefrom, simultaneously passing said medium through said package from said surface to an opposite surface thereof, and evacuating said medium from said opposite surface of the package to maintain flow through said package from one to the other of said surfaces' thereof.

ALPHEUS O. HURXTHAL. HAROLD G. BLACK. PHILLIPS K. SCHWARTZ. 

